Some diabetics taking chlorpropamide have an intense facial flush after alcohol. This chlorpropamide induced alcohol flushing (CPAF) is reported to be a dominantly inherited trait associated with non-insulin dependent diabetes. CPAF has also been reported to be present before the onset of glucose intolerance and therefore recommended as a genetic marker for some cases of non-insulin dependent diabetes. The Pima Indians, a population with the highest reported prevalence of diabetes in the world have the non-insulin dependent type of diabetes. We therefore used the chlorpropamide-alcohol flushing test to study this population, to determine the relationship between CPAF and non-insulin dependent (Type II) diabetes. Studies in the Pima have failed to show any relationship between CPAF and the presence of diabetes. Other groups have also not observed this association and therefore have failed to confirm the original observations of Leslie and Pyke.